Merge tag 'dm-4.8-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - another stable fix for DM flakey (that tweaks the previous fix that
   didn't factor in expected 'drop_writes' behavior for read IO).

 - a dm-log bio operation flags fix for the broader block changes that
   were merged during the 4.8 merge window.

* tag 'dm-4.8-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm log: fix unitialized bio operation flags
  dm flakey: fix reads to be issued if drop_writes configured

drivers/md/dm-flakey.c

@@ -289,15 +289,13 @@ static int flakey_map(struct dm_target *ti, struct bio *bio)
 		pb->bio_submitted = true;
 
 		/*
-		 * Map reads as normal only if corrupt_bio_byte set.
+		 * Error reads if neither corrupt_bio_byte or drop_writes are set.
+		 * Otherwise, flakey_end_io() will decide if the reads should be modified.
 		 */
 		if (bio_data_dir(bio) == READ) {
-			/* If flags were specified, only corrupt those that match. */
-			if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == READ) &&
-			    all_corrupt_bio_flags_match(bio, fc))
-				goto map_bio;
-			else
+			if (!fc->corrupt_bio_byte && !test_bit(DROP_WRITES, &fc->flags))
 				return -EIO;
+			goto map_bio;
 		}
 
 		/*
@@ -334,14 +332,21 @@ static int flakey_end_io(struct dm_target *ti, struct bio *bio, int error)
 	struct flakey_c *fc = ti->private;
 	struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
 
-	/*
-	 * Corrupt successful READs while in down state.
-	 */
 	if (!error && pb->bio_submitted && (bio_data_dir(bio) == READ)) {
-		if (fc->corrupt_bio_byte)
+		if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == READ) &&
+		    all_corrupt_bio_flags_match(bio, fc)) {
+			/*
+			 * Corrupt successful matching READs while in down state.
+			 */
 			corrupt_bio_data(bio, fc);
-		else
+
+		} else if (!test_bit(DROP_WRITES, &fc->flags)) {
+			/*
+			 * Error read during the down_interval if drop_writes
+			 * wasn't configured.
+			 */
 			return -EIO;
+		}
 	}
 
 	return error;

drivers/md/dm-log.c

@@ -291,9 +291,10 @@ static void header_from_disk(struct log_header_core *core, struct log_header_dis
 	core->nr_regions = le64_to_cpu(disk->nr_regions);
 }
 
-static int rw_header(struct log_c *lc, int rw)
+static int rw_header(struct log_c *lc, int op)
 {
-	lc->io_req.bi_op = rw;
+	lc->io_req.bi_op = op;
+	lc->io_req.bi_op_flags = 0;
 
 	return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 }
@@ -316,7 +317,7 @@ static int read_header(struct log_c *log)
 {
 	int r;
 
-	r = rw_header(log, READ);
+	r = rw_header(log, REQ_OP_READ);
 	if (r)
 		return r;
 
@@ -630,7 +631,7 @@ static int disk_resume(struct dm_dirty_log *log)
 	header_to_disk(&lc->header, lc->disk_header);
 
 	/* write the new header */
-	r = rw_header(lc, WRITE);
+	r = rw_header(lc, REQ_OP_WRITE);
 	if (!r) {
 		r = flush_header(lc);
 		if (r)
@@ -698,7 +699,7 @@ static int disk_flush(struct dm_dirty_log *log)
 			log_clear_bit(lc, lc->clean_bits, i);
 	}
 
-	r = rw_header(lc, WRITE);
+	r = rw_header(lc, REQ_OP_WRITE);
 	if (r)
 		fail_log_device(lc);
 	else {